Spark plug



F. A. HENKLE.

SPARK PLUG. APPLICATION FILED AuG.3, I92o 1,425,476, PaIenIedAug. s,192.2.

INVENTOR ATTORNEY WITNESS-F*d FRANK A. HENKLE, OF '.POMONA, CALIFORNIA.'

SPARKv rLUa Patented Aug. 8, 1922.

Application led August-3, 1920. Serial No. 400,928.

To all whom it may concern:

Be it known that I, FRANK A. HENKLE, a

`citizen of the United States, residing at Pomona, in the county of LosAngeles and State of California, have invented new and usefulImprovements in Spark Plugs, of which the Jfollowing is a specification.

' The object of my resent invention4 is the' provision of a slmple andpractical ls)p1ark plug of high eiiiciency and durai ity.

To the attainment of the foregoing the invention consists in theimprovement as hereinafter described and definitely claimed.

In the accompanying drawings, hereby made a part hereof Figure 1 is adiametrical section of a spark plug constructed in accordance with yminvention igure 2 is an elevation of the inner end of the plug.

Figures 3, 4, 5, 6, 7, and 8l are views re 2 and showing modificationshereina ter explicitly referred to.

Similar numerals designate corresponding parts in Figures 1 and 2 tokwhich reference will first be had.

Among other elements my spark plug comprises a metallic bushing 1,threaded at 2 for connection to the cylinder of an internal combustionengine and having an interior abutment 3 as well as a socket 4 in itsouter end, interiorly threaded at 5.

The innen portion of the bushing 1 is chambered as shown.

The spark plug also comprises a dielectric member 6 having in its innerend a' chamber 7 and also having abutments 8 and 9 and a longitudinalcentral bore 10. The dielectric member 6 is arranged in t-he bushing 1and is secured in position by the nut 11; gaskets 12 and 13 beinginterposed between the member 6 and the bushing 1 and between the nut 11and the abutments in the bushing 1 and on the member 6, respectively, asshown. The main electrode 14 which extends through the bore 10 of themember 6 is provided in the chamber 7 with an enlargement 15, on whichis arranged a gasket 16. All of the gaskets referred are preferably ofireproof material, and

they serve eifectively in preventing leakage through the plug. Mountedon the outer threaded portion of the main electrode 14 are the usualnuts 17 and 18. The elements thus far described are not of my nvention,though I prefer to use the construck tion of the bushm of the tion madeup to these elements because of 1ts practical utility.

In furtherance of my invention the main electrode 14 is arranged withits inner end substantially flush with the inner end of the bushing 1,and on the said inner end ofthe main electrode are steel bristles 19,`electrically connected with the main electrode and having their outerends separated by an annular space from the adjacent por- By virtueof'te provision of the steel bristles -19 arranged as set forth, it willbe manifest that on the suction stroke of an engine the brush formed bythe bristles will beflexed inwardly vto a slight extent, and on thecompresslon stroke explosive mlxture will be compressed through and pastthe bristles l9,and into the inner portion plug as shown in a chamberoposed to the bristles. The effect of this 1s to clear'and keep clearthe gap or the annular space between the steel bristle brushl and theinner end of the bushing 1.`

From this it follows that when current is su plied to the main electrode14 sparks wil jump from the ends of the bristles 19 to the adjacent' endof the ground bushing 1. Manifestly the explosion will be attended byjarring of the bristles sufficientl to displace any dry soot or oilAthat may ave accumulated thereon incident to the suction or compressionstrokes. It will also be apparent in this connection that when theexplosive mixture compressed in the chamber in the inner portion of thebushing 1l is exploded any soot collected on the face of the walls ofthe plug will be thoroughly burned by reason of the brush constructed ofthe bristles19 forming a deiector, calculated to spread the ame anddirect the same against the wall of the plug. It will be further notedthat any carbon that may collect at the inner end and the bristles 19cbeing carried by theinner bushing lb and being separated by an anlnularspace from the bristles 19h.

In the modification shown in Figure 5. a bunch or bunches of bristles19dl are carried on the bushing `l, and a complementary bunch or bunchesof bristles 19e are carried on the main electrode 14.

'In the modification shown in Figure 6 a bunch of bristles 19t carriedby the main electrode are arranged with their. outer ends in spacedrelation to the inner end of the bushing -lf.

In the modification shown in Figure 7 a head 14g is carried at-the innerendA of the main electrode and is provided with an arcuate face 14opposed to and separated from an arcuate series of bristles 19@electrcally connected with the bushing lg.

In the modification shown in Figure 8 a T-head li isopposed to andspaced from bristles 19j electrically connected with a bushing of groundelectrode l1.

Manifestly all of the modifications shown and described fall within thepurview of my broad invention which consists in the provision-of steelbristles between the main electrode and the bushing or ground electrodeat the inner end of a chamber rovided in the ortion of the bushing orground electro e.

Having described my invention, what l ments and separated by a gapbordered by free bristle ends vall in the same y plane from the otherelement.

2. A spark plug comprising a metallic bushing chambered at its innerend, a dielectric member disposed in the bushing and having alongitudinal central bore, a main electrode extending through the boreof the dielectric member and resting in the chamber of the metallicbushing, and bristles interposed between the inner portions of the mainelectrode and the bushing and disposed in a lane extending at rightangles to the lengtli thereof and carried by one of said members andseparated by a gap bordered by free bri'stle ends all in the same planefrom the other of said members.

In testimony whereof l aliix my signature. I

FRANK A. HENKLE.

